The emergence of the sound caused by the vibration of air / gas at the exit of the gas valve throat. This is a very common thing that can happen to anyone, and is an attempt to release the trapped air in the stomach which usually causes discomfort in the gastrointestinal tract.
if it happens constantly burp also caused by flatulence. Consuming foods and beverages that are too fast, feeling anxious and consume soft drinks are the most common cause for abdominal bloating.
At the time of burping, larynx, upper esophageal sphincter, the esophageal sphincter and diaphragm all work in accordance with the portion to set the rising and falling of air flow from the stomach to the esophagus in the chest.